Using Satellites to Protect Shark Sanctuaries

Sharks play an important and often overlooked role in the ocean ecosystem. As apex predators, or predators at the top of their food chain, sharks regulate the diversity and diets of species below them, ensuring a healthy ocean habitat. For instance, the decline of sharks in many areas has been shown to directly correlate with the demise of coral reefs and seagrass beds. Despite their importance, illegal shark fishing threatens roughly 25% of the world’s sharks with extinction.

Researchers at UC Santa Barbara’s Marine Science Institute tracked the movement of 15 grey reef sharks around the Marshall Islands where shark fishing is prohibited, and found that at least eight sharks had fallen victim to illegal fishing. In 2011, the Marshall Islands became home to the world’s largest shark sanctuary, passing legislation which protected sharks over roughly 2 million square kilometers surrounding the Pacific island. Despite the regulations, the commercial and black market value of sharks threatens to reduce the population of grey reef sharks in the region by more than 90% in the next five years.

To combat illegal fishing, new satellite technologies — traditionally used for navigation — are being used to track fishing vessels and their movement patterns across the ocean. Using satellite identification, ships are tracked via unique identification numbers, which more readily allow for careful monitoring of fishing practices and will hopefully discourage vessels from engaging in illegal activities. The benefits of tracking ships in near real-time extend beyond just protecting sharks, such as allowing for more careful monitoring of “transshipments”, or the undocumented transfers of illegal catches to new ships, which is often how illegally-caught fish end up in markets. Although a number of shark sanctuaries are being created in regions around the world, their efficacy ultimately depends on our ability to regulate and enforce legal fishing practices in the area.